Mill for grinding ores



2 Sheets-Sheet 1.

(No Model.)

M. O. & J. M DAVIS. Mill for Grinding Ores, 8L0.

2 S I V A D M J ow C M Mill for Grinding Ores, 8L0.

No. 233,401. Patented Oct. 19,1880.

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UNITED STATES PATENT OFFICE.

MYRON O. DAVIS AND JOSEPH M. DAVIS, OF WORCESTER, MASSACHUSETTS.

MILL FOR GRINDING ORES, 840.

SPECIFICATION forming part of Letters Patent No. 233,401, dated October 19, 1880.

Application filed March 8, 1880. (No model.)

To all whom it may concern Be it known that We, MYRON O. DAVIS and JOSEPH M. DAVIS, ofthe city and county of Worcester, State of Massachusetts, have invented an Improved Ore-Mill, of which the following is a specification.

Our invention relates to that class of mills which is used in reducing to a finely-powdered state extremely hard substances, the objects of the invention being to avoid the objections tov mills of the ordinary construction, prevent the grooving or channeling of the burrs, maintain the uniformity of the periphery of the burr, and rapidly distribute the product according to its fineness.

In the drawings forming part of this specification, Figure l is a sectional elevation ofa mill, showing our improvements. Fig. 2 is a rear elevation, partlyin section and Fig. 3, a perspective view of one of the slides.

The frame is of any suitable construction, according to the purpose and character of the mill, that shown consisting of two side frames, A A, and curved edge plates 00 a, which, with the side frames, form a chamber terminating in a neck, 00, and containing the cylindrical stone 12, carried by the shaft 0.

Upon a horizontal bearing of each side piece rests a slide, B, from which a trunnion, 6, extends into a socket in the shell 0, curved to coincide with the face of the cylinder, and having at the bottom a bearing for the end of a screw-shaft, d, turning in a cross-piece, f, of the frame, and provided with a hand-Wheel. Each slide B has a limited horizontal movement on its bearing, imparted by a pinion, g, on a cross-shaft, h, turning in bearings of the frame and gearing with a rack on the slide. Between guides upon the inner faces of the side frames slide blocks j, carrying a shaft, 13, and adjusted by screws 70. Upon the shaft i is mounted, so as to turn with, but to slide independently of, the shaft, acylinder, D, which bears with its face upon the stone 1), and is driven at the same or at a slightly-difi'erent speed by a belt passing round pulleys on the shafts c i.

A hopper, I, at the top of the machine, has its outlet above a pivoted distributing-plate, m, the lower end of which is above the line,

Where the peripheries of the stone b and cylinl der D are in contact. The plate m rests on a shaft, 12, having lugs which strike the plate, and by jarring the same feed the pulverized material between the two stones, a slide, 8, regulating the flow.

At the ends of the cylinder D are cams t t, which have their bearings on anti-friction rollers u a, carried by the slides j, the construction of the cams being such that a longitudinal movement is imparted to the cylinder as it revolves.

The neck .2? communicates with an inclined chute, p, at the lower end of which is a fan, q, and at the under side openings 1', at different distances from thefan.

The stone, cylinder, and shell may be of cast metal, or of dilierent materials combined, or of any other material suitable for the purpose for which the mill is employed. .I prefer, however, to use for the reduction of hard substances, as manganese, the hardest French burr.

The material to be reduced is first broken to small pieces of uniform size, and is deposited in the hopper and fed over the plate m, between the stones 1) D, by which it is further reduced, not only by the crushing action of the rotating cylinders, but also by the grinding action resulting from the sliding of one stone upon the other. After passing from the cylinder D the material is carried between the finely comminuted, after which it falls into the chute p, and is blown upward, the heaver particles falling through the lowest passage, 4, and the lighter particles being carried farent openings, according to their gravity, the lightest and finest passing out at the end of the chute.

The lateral movement of the cylinder may be imparted in any suitable manner, and the stone b and shell 0 may likewise be moved laterally, not only grinding the material, but preventing the grooving or channeling, which is almost inevitable when no such motion is imparted.

The exact extent of the grinding and crushing action may be regulated by turning the shafts k d h, thus adjusting the cylinder and the shell at any distance from the stone 1), and

faces of the stone 1) and shell 0, and is therebyther upward, and descending through differthe suspension of the shell on the trunnions 0 permits the same to be adjusted at either end, to form a gradually-contracting opening, or otherwise.

By adjusting the slide 8 the exact quantity of material which is capableofbein g thoroughly crushed by the preliminary roll Dmay be passed to the latter.

One of the results of moving the cylinder D longitudinally is the truing of the face of the stone b, which is thus kept in working condition.

By arranging the hopper. the cylinder D, shell 0, and stone b as described, the material falls from the hopper directly between the stone 0 and cylinder D, and receives its preliminary crushing between the two, and cooperates with the cylinder 1), which travels at a different speed from the stone in truing the face of the stone.

\Vc are aware that crushing-cylirders have been combined with the stone and its concave, one of said cylinders revolving in contact with the stone; but in such case only a small portion of the material passes between the stone and its cylinder, and two cylinders are required, while by our arrangement all the material passes between the stone and its cylinder, and but one stone is needed.

As the slides B are adapted to horizontal bearings, and as the shaft h gears both slides together, one cannot move without the other either forward or backward, and the absolute parallelism of the concave and stone is preserved, while the concave having a bearing upon the fixed end of the screw d, any tendency to force out the top of the concave away from the stone will cause the slides to be pressed down upon their bearings and hold them frictionally in position.

\Ne claim- 1. The combination of the stone b, shell 0, cylinder D, geared to revolve at a different rate from the stone, and hopper arranged, as described, to discharge its con tents between the stone and the cylinder, as shown and described.

2. The combination of the shell 0, stone 1), cylinder D, rotating in contact with said stone, and appliances for reciprocating the cylinder longitudinally, as set forth.

3. The combination of the shell U, slides B, having horizontal bearings, and both geared to a transverse shaft, 12., and lower bearing for the shell 0, as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

MYRON G. DAVIS. JOSEPH M. DAVIS.

\Vitnesses:

COURTNEY A. COOPER, Geo. W. PEARSON. 

